Hey I modified script for php 5. Also I add support server auth. and fixed some little bugs on the script.

[EDIT BY danbrown AT php DOT net: Original was written by (unlcuky13 AT gmail DOT com) on 19-APR-09. The following note was included:
Below is the my way of using through PHP 5 objecte oriented encapsulation to make thing easier.]

I needed to use cURL in a php script to download data using not only SSL for the server authentication but also for client authentication.
On a default install of Fedora, setting up the proper cURL parameters, I would get an error:

After a lot of frustration with the fact that nobody has documented which curl commandline options go with which library functions, I discovered that the curl commandline will tell you (in the form of a C program) if you add `--libcurl foo.c`

If you've been struggling with trying to figure out how to get your fancy curl commandline to work in PHP, this makes it a breeze!

A solution that addresses repeat calls to the same set of urls using the same connection simulating frequent ajax calls in separate browser tabs.

In a unique situation you may need to set a cookie then use that cookie for multiple separate persistent connections using the same session cookie. The problem is the session cookie may change while your doing your persistent calls. If you set every curl handle to update a shared cookiejar on close you may overwrite the new found session value with the old session value depending on the closing order of your handles. Also, because the cookiejar is only written to on a curl_close, you may be using dissimilar or old session info in some of your 'faked browser tabs'.

To solve this problem I created a unique handle that opens and closes specifically to set a cookie file using CURLOPT_COOKIEJAR. Then I just use the read-only CURLOPT_COOKIEFILE on the multiple separate persistent handles.

This solves the problem of shared cookies fighting to write their values and keep persistent calls using the most up to date cookie information.

Note: In my case the multiple calls were in a while loop and I was using php in shell. The session cookie value plus browser type limited the number of connections available and i wanted to use the max connections per session.

I wanted to create a script that acted as a bridge between an external server and an internal server, wherein the internal server was not connected to the internet, but had information required by the users connecting to the external server. I hatched the idea to use curl to connect from the external server to the internal server (using request variables to send queries) and return everything (data and headers) returned by the file server.

After being driven mad by segmentation faults and crashes because the curl_exec didn't like me having the CURLOPT_HEADERFUNCTION's function directly dumping the header: